The FDA says Johnson & Johnson's (JNJ+0.1%) diabetes drug Invokana was effective at lowering a key measure of blood sugar, but the agency raised concerns about potential stroke and bone-related safety risks. The drug is due to be reviewed on Thursday by the FDA's endocrinologic and metabolic drugs advisory committee, which is made up of non-FDA medical experts. The agency released its review of the product today in preparation for the panel meeting.